Biogeographic memory

[John R. Grehan]

For those interested I have responded so the points most recently raised by
Hovenkamp with some additional comments on the different findings of
panbiogeography and cladistic methods for the South East Asia region.


>If that is your notion of censorship - please do not use the word in
>correspondence that is read outside America. Real censorship is still an
>issue in many parts of the world.

Self censorship is still censorship and no less a real than any other form
of censorship.


>Do you mean it was accepted after the reference was omitted - or were
>there more points that needed revision?

I know of a case with a prominent journal where the editor declared that
there would be no papers published in his journal that cited Croizat and
turned down publication of a paper on that basis. Soon after the editor
passed away, and the next editor allowed the paper to be published. This
kind of censorship is very real and has had a very real influence on the
dissemination of panbiogeography.

>All of Croizat's discussions are totally without reference to the value of
>resolved schemes of relationships.

I believe this is questionable, but it may depend on whether Croizat's
comments on these issues met the criteria in mind.
Croizat (1968) for example, notes the outstanding value of Corner's
checklist on Ficus in that it provided such a detailed taxonomic
arrangement that is was possible to associate progressively narrower
affinities etc. Throughout Croizat's works there is a consistent use of the
major systematic/taxonomic monographs of the time, thus emphasizing the
need for the best available phylogenetic information. Perhaps at would make
an interesting historical document to specifically address how Croizat
used, commented on, and applied systematic studies and what the long-term
implications have been.

>Likewise, in your book you are stressing that biogeographic analysis is
>prior to the establishment of a natural classification.

A natural classification being a combination of form and spatial relationships.


>I quote again (p. 6): "their distributions are not distinguishable
>according to their different means of dispersal".
>A simple test: put the two maps before a reasonably well-informed audience
>- ask them to indicate which of the two is more likely to be a group of
>butterfly, which of freshwater fish.

And I would repeat that they are not distinguishable by means of dispersal.
There is no objective criterion for deciding which is which based on means
of dispersal.

I believe the points raised by Hovenkamp show that Croizat's works are in
deed relevant to all aspects of biogeography and while we may disagree on
the use of "censorship" to describe citation or the lack of it, the absence
of citation in this case is telling. For example, a colleague of mine noted
how the opening sentence of the abstract says the biogeography of Southeast
Asia and the West Pacific is "complicated" by the bordering of two
paleocontinents. In contrast Croziat's analyses suggests the biogeography
is not complicated in this respect. Then the final sentence is even more
telling: "We have not been able to trace common patterns." This is where
historical citation or lack of may become critically important. If Turner
et al are not able to trace common patterns by their methodology where does
this leave Southeast Asia Biogeography? Is this the status quo? Is this an
advance? The absence of citation of Croizat's work may lead to a very
different impression than what might otherwise be made if his works were
cited and discussed as Croizat's methodology did lead to the discovery of
common patterns. That being the case one might discuss the relative merits
of a method that does trace common patterns in the region and a later
method that does not.

John Grehan

John Grehan
Frost Entomological Museum
Pennsylvania State University
Department of Entomology
501 ASI Building
University Park, PA 16802. USA.

Phone: (814) 863-2865
Fax: (814) 865-3048

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